为了能很好地鉴别碎片质量,建立一个好的飞行时间测量方法是十分必要的。阐述了建立用于裂变碎片质量测量的微通道板(MCP)和金硅面垒探测器(SBD)飞行时间探测系统。对于80μg/cm2厚的碳膜,241Am的α粒子的探测效率约为39%,252Cf(sf)裂变碎片的探测效率约为98%。在动能为78 MeV条件下,对252Cf(sf)重裂变碎片(138~148 u)得到的时间分辨为(224.1±6.1)ps;在动能为102 MeV条件下,对252Cf(sf)轻裂变碎片(101~111 u),得到的时间分辨为(154.5±5.8)ps。
In order to separate the mass number of fragments in the fission reactions, it is essential to develop a good time-of-flight(TOF) method. The purpose of this article is to set up a TOF detector system including a microchannel plate(MCP) and a Au-Si surface-barrier detector(SBD). The TOF system shows a detection efficiency of 39% for α-particles released from ~(241)Am and 98% for fragments in the spontaneous fission of252 Cf.The experimental results show that the time resolutions of(224.1 ± 6.1) ps for the heavy fragments(Ek= 78 Me V, AH = 138 ~ 148 u) and(154.5 ± 5.8) ps for the light fragments(Ek= 102 Me V, AL = 101 ~ 111 u) can be obtained.